What is the purpose of the crank position sensor on a Toyota Corolla and what does the car do when the sensor malfunctions?

Answer by  tony91 (73)

It senses when the #1 piston is at top-dead-center, and tells the CPU when to send spark to spark plugs in relation to piston position. When sensor malfunctions, 'service engine soon' will light, and a diagnostic trouble code can be read using an OBDII code reader.

Answer by  Raf (146)

A crank position sensor helps the car start smoother when starting. By knowing where the crank is positioned it helps with timing and a malfunction can cause a "rough" start.

Answer by  Amber40 (24961)

The main purpose of the crank position sensor is to know how fast the engine is spinning. The ecm uses this info to calculate when to fire the plugs as well as the injectors. When it malfunctions the engine is thrown out of sync. The engine run erratically.

Answer by  japratt (1687)

The sensor is more there just to control what is happening with your car. If the senor actually does go out you should still not really have any lasting problems.

Answer by  oui72 (514)

The crank position sensor determines the revolution of the engine. This sensor feeds essential information to other functions. When sensor malfunctions efficient and valve timing could be affected. It could be like you on a spending spree with multiple credit cards.